Zebra danio rehabilitation

I know someone who has a fish tank filled with glo tetras, and a single Zebra danio. The danio is bullied so much its fins are in tears. I want to bring him to my house to keep in one of my 2 tanks but I don't know the temperament of the fish. Option 1, 20 gallon with Betta. Carl, my Betta, does not like shrimp, but idk about danios. (About to add more plants to tank.) Option 2, 2.5 gal with shrimp. my 2.5 gal has lots of plants and 6 adult cherries. Please tell me what to do, or if someone else should help it.

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